I have a dedicated web server 220.127.116.11. My customers are advised to use mail.theirdomainname as incoming server and smtp.theirispname as outgoing. Some persist in using mail.theirdomainname as the outgoing server.
If a customer then sends out mail deliberately or unintentionally that is regarded as spam it can result in the server being blocked.
I accept that this can happen and try to discipline customers to not send out possible spam, but obviously have little control over this.
I have a number of questions:
1. How can I identify which email address is responsible for the problem?
2. I was told that most smtp services use a bank of mail servers and randomly pick a server to send out from, thus limiting the chances of being blocked. Is this correct?
3. I've told my customers that if they use their ISP's smtp service there is little chance of being blocked. Ids this correct?
4. I use my ISP's smtp service (smtp.afrihost.co.za) but my emails are now being returned because my web server (18.104.22.168) is blocked. How can this be? Here's one message:
A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed:
(ultimately generated from roger[at]certsa.co.za)
SMTP error from remote mail server after RCPT TO:<rogerc[at]rolyfin.co.za>:
host mxc02.mxrc.co.za [22.214.171.124]: 550-rejected because 126.96.36.199 is in a black list at bl.spamcop.net
550 Blocked - see http://www.spamcop.net/bl.shtml?188.8.131.52
If I am using smtp.afrihost.co.za (which is not on my server) and not mail.mydomain why is the web server reported? Is it possible that spamcop has identified the web server of my domain (and therefore my email address) and listed it as the offending server? If that's the case won't that affect all domains on my server, even if they are using their ISPs?
I'm very confused, help please.